Rolling cutter and seals therefor

ABSTRACT

In cutters having a rolling cutter and a journal around which the cutter rolls there are bearing members. In cutting rock and earth formations it is necessary to keep out the rock, earth, and extraneous material from the bearings. This invention is directed to seals for sealing the bearings in their working cavity in the cutter so that dirt, rock, and extraneous material cannot reach the bearing and harm and damage the bearing surfaces.

United States Patent Dougles F. Winberg 3,332,505 7/1967 Schumacher 175/372 3,389,760 6/1968 175/371 3,449,024 6/1969 175/371X 3,480,341 11/1969 Hickernell 175/372X Primary Examiner-Marvin A. Champion Assistant ExaminerRichard E. Favreau AttorneyThomas W. Secrest ABSTRACT: In cutters having a rolling cutter and a journal around which the cutter rolls there are bearing members. In cutting rock and earth formations it is necessary to keep out the rock, earth, and extraneous material from the bearings.

This invention is directed to seals for sealing the bearings intheir working cavity in the cutter so that dirt, rock, and ex-' traneous material cannot reach the bearing and harm and damage the bearing surfaces.

Patented March 30,1971 3,572,452

5 Sheets-Sheet 1 1 VENTOR.

pay/$ BY Mic/252' R TORNEV 5 Sheets-Sheet m W Mi w Z z i I 1 I50 Y m 7 a We um w w w 8 Sheets-Shoot I INVENTOR. 353 3.3! 009/4: F 1 0112? A T TORNE P QOLLING CUTTER AND SEALS THEREFOR In cutters having a rolling cutter and a journal around which the cutter rolls, there have been used various types of seals. One of these types of seals has been two metal rings. Each ring has a sealing surface. The sealing surfaces of the two metal rings seat with each other. One of the metal rings is stationary as it is closely associated with the journal. The other metal ring is movable and rotates or revolves with the rotation of the rolling cutter. Two sealing surfaces of the metal ring, after sufficient rotation of the rolling cutter, seat themselves. In the manufacture of these metal rings, it is expensive to form the two metal rings and to finish the sealing surfaces of these two rings so that initially extraneous matter or dirt or pieces or rock cannot work between the two sealing surfaces before the two metal rings are properly seated.

From having worked with drilling equipment, mining equipment and tunnel-boring equipment for a number of years, I have learned to appreciate some of the problems involved with the existing seal and therefore I have made this invention using graphite-to-graphite seals and graphite-to-metal seals. Accordingly, it is an object of this invention to provide a new combination of sealing surfaces for cutters used in mining, tunnel boring and well drilling; a further object is to provide sealing surfaces which have less friction than presently employed sealing surfaces; an additional object is to provide sealing surfaces which are self-lubricating under existing operating conditions; a still further object is to provide sealing surfaces wherein it is easier and quicker to seat the sealing surfaces with respect to each other; a further object is to provide a cutter and a saddle wherein the cutter can be readily positioned in the saddle for holding the cutter; another important object is to provide sealing surfaces which are less expensive to manufacture and to maintain than metal-to-metal sealing surfaces; a still further important object is in one version to provide sealing surfaces wherein there are two fewer separate seal members as such than in the prior existing cutter; in one version of the sealing surfaces to provide means for positively urging together the two sealing surfaces; a still further object is to provide seals having longer wear life than conventional prior seals; to provide seals which give better protection of bearings and the seats for the bearings and their inner components of the machinery; to provide seals which, if a lubricant is used, substantially eliminate all leakage of the lubricant through the seal basis; to provide seals having a high corrosion resistance; and, to provide seals having good dimensional stability over a wide temperature range encountered with the production of heat through the rubbing of solid members.

These and other important objects and advantages of the invention will be more particularly brought forth upon reference to the accompanying drawings, the detailed description of the invention and the claims.

In the drawings:

FIG. 1 is a fragmentary longitudinal cross-sectional view of one specific embodiment of the invention constructed in accordance with the preferred teaching thereof and illustrates a graphite-to-metal seal;

FIG. 2 on an enlarged scale, shows the graphite-to-metal seal and illustrates a spring for urging together the graphite and metal sealing surfaces;

FIG. 3 is a front elevational view and illustrating the rolling cutter in the saddle and means for positioning the rolling cutter in the saddle;

FIG. 4 is an end elevational view illustrating the rolling cutter in the saddle and the means for maintaining the rolling cutter in the saddle;

FIG. 5 on an enlarged scale, illustrates another form of seal between a graphite surface and a metal surface and shows a retainer ring on the edge of the graphite seal;

FIG. 6 is a fragmentary, longitudinal cross-sectional view illustrating two sets of graphite seals comprising two graphite seals each and with the sealing surfaces in each set in contact with each other;

FIG. 7 on an enlarged scale, is a fragmentary cross-sectional view illustrating another form of a set of two graphite seals and with the retainer ring on the outside edge of each graphite seal;

FIG. 8 illustrates another specific embodiment of a set of two graphite seals and with a protective member between the graphite surface and a flexible yieldable ring,

FIG. 9 taken on line 9-9 of FIG. 6, is a fragmentary crosssectional view illustrating a dowel pin for positioning a seal gauge on the journal;

FIG. 10 taken on line 10-10 of FIG. 1 is a diametrical crosssectional view illustrating the thrust hearings in the cutter and means for maintaining the thrust hearings in the cutter;

FIG. ll taken on line 11-11 of FIG. 1, is a diametrical cross-sectional view illustrating a graphite seal and the flexible yieldable ring bearing against said graphite seal and a solid rigid member of the cutter; and

FIG. 12 taken on line 12-12 of FIG. 1, is a diametrical cross-sectional view illustrating a graphite seal and the yieldable flexible member bearing against a portion of the rolling cutter and a protective surface for the graphite seal.

In the drawings, and in particular, FIGS. 3 and 4, there is illustrated a cutter 20 and a saddle 22 for holding the cutter in position.

The saddle 22 comprises a base 24 and a leg 26 and a leg 28. In FIG. 3 it is seen that the saddle 22 is of a generally U-configuration. In FIG. 4 it is seen that the legs taper upwardly and inwardly from the base and the top portion of each leg is a curve 30. p

In the inner surface of each leg 26 and 28 there is a slot 32. The slot 32 tapers outwardly or becomes larger as the slot proceeds from the throat to the interior of the leg. At the throat slot 32 has an opening 34 while interiorly of the throat the slot 32 has a sidewall or edge 36. It is seen that the area encompassed by 36 is larger than the area encompassed by the throat 34.

In each leg there are two passageways 38 extending from the outer surface of the leg tothe surface of the slot. Each' passageway 38 is countersunk at 40 in the outer surface of the leg.

There is a keeper 42 and which keeper 42 is internally tapped at 44 for receiving bolt 46 in passageway 38. The cutter 20 has a journal in the interior and which journal has a hub 50 on each end. The hub 50 expands outwardly at 52 so as to fit with the slot 32 in the saddle 22. Actually, the hub 50 may be considered the equivalent of a tongue and the slot 32 may be considered the equivalent of a groove. Therefore, the hub and slot may be considered to be a tongue and groove engagement. The keeper 42, after the cutter 20 is positioned in the saddle 22, prevents the cutter 20 from moving out of the saddle 22 and prevents the hub 50 from moving out of the slot 32.

In FIG. 6 there is illustrated a preferred embodiment of a cutter 60 and which cutter 60 has a journal 62 and a rolling cutter 64.

The rolling cutter 64 rolls around or rotates around the journal 62. The journal 62 is substantially stationary while the rolling cutter 64 is free to rotate around it.

In the construction of the cutter 60 the rolling cutter 64 slips over or moves over the journal 62 and then is locked in positionon the journal 62 so that the rolling cutter 64 cannot move longitudinally on the journal 62 but is free to revolve or rotate around the journal 62.

The journal 62 has a central longitudinal passageway 66. There connects with this central longitudinal passageway 66 a radial passageway 68 at right angles to the passageway 66.

In FIG. 6 it is seen that to the left of the radial passageway 68 that there is a circular or encircling seat 70 in the journal To the left of the circular seat 70 the journal 62 recedes in diameter and there is a recess 72 for receiving a dowel pin 74. The recess 72 is actually a radial recess for receiving the dowel pin 74 which functions as a lock or a setpin. The recess 72 is circular and radial.

To the left of the recess 72 there is an encircling recess or a circular recess 76 in the journal 62. This recess 76 receives an O-ring 78 and which O-ring 78 functions as a seal.

To the left of the encircling or circular recess 76 there is an encircling or circular recess 80. In the recess 80 there is a snap ring 82.

There is positioned on the journal 62 a seal gauge 90. The seal gauge 90 encircles a left portion of the journal 62 and has a surface for engaging the O-ring 78 so as to prevent extraneous and foreign material entering the interior of the journal 62 and the rolling cutter 64. The seal gauge 90 projects outwardly and has a relau'vely thin wall 84. Then, the seal gauge 90 projects inwardly to form an outer circular flange 96.

In FIG. 6 it is seen that part of 92 of the seal gauge 90 projects inwardly or toward the radial passage 68 in the form of a leg 98. In the leg 98 there is an opening 100 for receiving the dowel pin 74. With the dowel pin 74 in position in the recess 72 in the journal 62 and also in position in the opening 100, the seal gauge 90 is locked with respect to the journal 62. In FIG. 6 it is seen that to the right of the radial passageway 68 that there is an encircling seat 110. To the right of the encircling seat 110 there are a number of drilled circular recesses 1 12 for receiving a dowel pin 1 14. p

To the right of the drilled circular radial recesses 112 there is an encircling recess 116 for receiving an O-ring 118. The O- ring 1 18 functions as a seal.

To the right of the encircling recess 116 there is an encircling recess 120 for receiving a snap ring 122.

There is a seal gauge 124 and which seal gauge has an inner circular flange 126. The inner circular flange 126 has an opening or a recess 128 for registering with the circular recess 112. In the recess 112 and in the recess 128 there is positioned the dowel pin 114 for locking the seal gauge 124 with respect to the journal 62.

The seal gauge 124 has an outwardly directed thin wall member 130. Then, the seal gauge 124 is directed inwardly in an outer circular flange 132.

The rolling cutter 64, in its inner surface, has an encircling groove 140. To the left of the encircling groove 140 there is an encircling seat 142 and which seat is aligned with circular seat 70 of the journal 62. Between the seat 70 and the seat 142 there are roller bearings 144. To the left of the seat 142 there is an upwardly and outwardly sloping surface 146. Then, the sloping surface 146 rises upwardly into a step 148 and outwardly into the outwardly directed flange 150. It is seen that the rolling cutter 64 and the seal gauge 90 are separated and are not in contact at 150 in the upper part of the encircling flange 96.

To the right of the encircling groove 140 there is an encircling seat 152. Between the encircling seat 110 of the journal 62 and the seat 152 there is positioned a roller bearing 154.

To the right of the encircling seat 152 there is an upwardly and outwardly directed sloping surface 156. Then, the surface 156 goes into an outwardly directed step 158. 158 then is directed outwardly in a flange 160. It is seen that the flange 160 and the outer circular flange 132 of the seal gauge 124 are separated and are not in contact.

In the encircling groove 140 there is a series of ball bearings 162. The ball bearings act as thrust bearings to prevent the longitudinal movement of the rolling cutter 64 on the journal 62. Further, the ball bearings also act as radial bearings in conjunction with the roller bearings 144 and 154.

A plug 164 in the radial passageway 68 positions the ball bearings 162 in the encircling groove 140 and also in the passageway 68. There is a shaft 166 in the central passageway 66 of the journal 62. The lower part of the plug 164 has an encircling recess 168. The shaft 166 has an encircling recess 170. The lower part of the plug 164 has encircling recess 168. The shaft 166 has an encircling recess 170. In the recesses 168 and 170 there is an O-ring 172 for positioning the shaft 166 with respect to the plug 164.

The journal 62 to the left of the circular seat 70; the seal gauge with respect to the leg 98, the thin wall 94, and the encircling flange or outer circular flange 96; and, the rolling cutter with respect to the sloping 146, step 148, and flange 150; and, the roller bearing 144 define a cavity 180 for receiving seals. Likewise, the journal 62 to the right of the encircling seat 110; the inner circular flange 126, the thin wall 130, and the outer circular flange 132 of the seal gauge 124; the sloping 156, the step 158 and the flange 160; and, the roller bearing 154 define a cavity 182. In each of the cavities 180 and 182 there is a set of seals. The seals in the cavity 180 are of a larger diameter than the seals in the cavity 182. However, the general configuration of the seals is the same and the function is the same and therefore these seals will be described with the same reference numerals.

The seals comprise a circular ring 190. There are two circular rings 190 in the cavity 180 and there are two circular rings 190 in the cavity 182. The rings 190 comprise an annular sealing surface 192. The lower part 194 of the ring 190 recedes inwardly and away from the annular sealing surface 192. The upper surface 196 of the ring 190 slopes downwardly and away from the upper part of the sealing surface 192 and then rises upwardly at 198. This leads to a trough 200 in the upper surface of the ring 190. There is positioned in the cavity 180 and between the outer circular flange 96 and the upper surface 196 of the outer ring seal 190 a yieldable flexible O-ring 202. Likewise, there is positioned between the sloping surface 146 of the rolling cutter 64 and the upper surface 196 of the inner ring seal 190 a yieldable flexible O-ring 202. It is seen that the yieldable flexible O-ring 202 force together the sealing surfaces 192 of the ring or seal 190.

Likewise, there is positioned between the outer circular flange 132 and the upper surface 1960f the seal 190 a yieldable flexible O-ring 202 and there is positioned between the sloping surface 156 and the upper surface 196 of the ring or seal 190 a yieldable flexible O-ring 202. Again, the O-rings 202 force together the sealing surfaces 192 of the seals 190 in the cavity 182.

The seals 190 are of graphite. The O-rings 202 are of a yieldable flexible material such as rubber or a plastic such as polyurethane. As is well known, the graphite sealing surfaces 192 have very little rubbing friction and easily slide over each other. Further, the graphite surfaces are self-lubricating and with a small amount of moisture there may be formed a chemical complex or a physical complex between the graphite and the moisture and which complex has a very low coefficient of friction and allows the seals to slide over each other. The function of the seals 190 and the O-rings 202 is to prevent extraneous material, dirt and rocks from entering the bearings I54, 162, and 144. By preventing the entrance of extraneous material, rock and dirt into the bearings, the life of the bearings is considerably increased.

In the journal 62 there may be passageways 210 for introducing lubricant into the roller bearing 154, ball bearing 162, and rollerbearing 144. The passageways 210 are in the hub of the journal 62. Appropriate fittings 212 may be used for sealing these passageways so that extraneous material cannot enter through the passageways.

The lubricant may be introduced for lubricating the roller bearings 314 and 332, and the ball bearings 350. In addition to lubrication of the roller and ball bearings, a lubricant, such as an oil, may be introduced as a cooling fluid. The lubricant contacts the rubber O-rings and the graphite seals, and if there be a metal protection plate on the seals, then the lubricant contacts the metal protection plate, so as to absorb heat and upon circulating and contacting the metal of the cutter to evenly distribute this heat in the cutter. In fact, in this situation, the lubricating oil is functioning as a heat transfer fluid for dissipating heat generated by the rubbing together of two solid surfaces, i.e., the sealing surfaces of the graphite seals.

In FIG. 7 there is illustrated a modification of the seals. This modification is identified by reference numeral 222. In each of the cavities and 182 there may be positioned a set of two seals 220. Each of these seals 220 is in the configuration of a ring and has an annular sealing surface 222. The annular sealing surface 222 of one seal 220 seats with the annular sealing surface 222 of the other seal 220. The seal inwardly of the annular sealing surface 222 recedes downwardly and outwardly at 224 from the sealing surface 222. The upper surface of the seal 220 slopes downwardly at 226 as it slopes away from the sealing surface 222. There is an outer edge 228. There is attached to the outer edge 228 a ring 230 of a flexible, yieldable material. On the outside of the ring 230 there is a hard, protective ring 232. The ring 230 and the ring 232 project above the junction of the upper surface 226, and the edge 228. There is positioned an O-ring 202 between the surface 226 and the sloping surface 146 or between the surface 226 and the outer circular flange 96 or between the surface 226 and the sloping surface 156 or between the surface 226 and the outer circular flange 132. The seals 220 are of graphite. The O-rings 202 and the retainer ring 230 may be of rubber or of plastic such as polyurethane or of other suitable, yieldable, flexible material. As is seen the O-rings 202 urge the seals 220 into contact with each other so that the surfaces 226 seat with each other. The ring 232 may be of metal or a suitable, hard, protective plastic. The ring 230 is bonded to the edge 228 of the seal 220 and the ring 232 is bonded to the ring 230. The rings 230 and 232 are retainer rings and may assist in preventing the O-rings 202 from rolling off the outer edge of the seals 220.

In FIG. 8 there is illustrated another modification of a seal 240. This seal 240 has annular sealing surfaces 242. In each of the cavities 180 and 182 there is a set of two seals 240. The sealing surfaces 242 seat with each other. The seals below the sealing surfaces 242 slope away from each other at 244. Also, the upper surfaces 246 of the seals 240 slope downwardly as the upper surfaces go away from the upper part of the annular seals 242. The outer edge of the seals 242 is identified by reference numeral 248. On most of the upper surface '246 and extending around the edge 248, there is a flexible, yieldable ring 250. The flexible, yieldable ring 250 is adhered or attached to the upper surface 246 and the edge 248 of the seal 240. Positioned outside of the ring 250 there is a hard, protective ring 252. The hard, protective ring 252 covers the upper surface 246 and the edge 248 of the seal 240.- The hard, protective ring 252 protects the flexible, yieldable ring 250. An O-ring 202 is positioned between the hard, protective ring 252 and an outer circular flange 132 or between the hard, protective ring 252 and the sloping surface 156 or between the hard, protective ring 252 and the sloping surface 146 or between the hard protective ring 252 and the outer circular flange 96. The O-ring 202 and the yieldable, flexible ring 250 may be of rubber or plastic such as polyurethane or other suitable material. The hard, protective ring 252 may be of metal or of a suitable plastic. In FIG. 8 it is seen that the rings 250 is a set of seals 240 and the rings 252 in a set of seals 240 do not contact each other. As is well known, the annular seals 242 of the seals 240 will wear so as to seat themselves and in time the rings 250 in a set and the rings 252 in a set will move closer to each other. Therefore, initially, it is necessary to have the rings in a set spaced apart from each other.

In NOS. 1, 10, 11 and 12, there isillustrated another cutter 300 having a journal 302 and a rolling cutter portion 304.

In the journal 302 there is a longitudinal central passageway 306 for receiving a shaft 308.

In approximately the central part of the journal 302 there is a radial passageway 310 and which passageway 310 is at right angles to the passageway 306.

In the journal 302 and to the left of the radial passageway 310, as seen in FIG. 2, there is a radial seat 312 for receiving a roller bearing 314. To the left of the radial seat 312, there is a circular groove 316 for receiving a snap ring 318.

To the left of the circular groove 316, the journal 302 rises upwardly into a wall 320. In the wall 320 there are a series of recesses 322. The wall 320 rises outwardly and curves inwardly to form a circular flange 324. The circular flange 324 has a sloping surface 326.

To the right of the radial passageway 310, as viewed in FIG. 2, there is a radial seat 330 for receiving a roller 332.

To the right of the radial seat 330 there is a circular shoulder 334. The circular shoulder 334 has an annular seat 336. Then, the journal 302 narrows in diameter and presents a substantially smooth radial surface 338 to the edge of the journal.

The rolling cutter has a generally central circular groove 350 for receiving ball bearings 351. To the left of this groove 350 there is a radial seat 353 for seating the roller bearing 314.

To the left of the radial seat 352, there is an annular seat 354. The annular seat 354 is a sealing surface for part of the seal. Then, the rolling cutter 304 increases in diameter to form the smooth radial surface 356.

To the right of the central circular groove 350, the rolling cutter forms a smooth, radial surface 358. In the surface 358 there is a circular notch 360, and in the notch 360 there is a snap ring 362.

The rolling cutter 304 is directed inwardly to form a wall 364. in the wall 364 there are a number of recesses 366. Then, the wall 364 of the rolling cutter is directed inwardly to form an inner circular flange 368.

The roller bearing 314, the journal and wall 320, and the circular flange 324 in conjunction with the smooth radial surface 356 and the annular seat 354 define a first cavity 380. The smooth radial surface 338, the annular seat 336, the wall 364 and the inner circular flange 368 define a second cavity 382.

In the configuration shown in FIGS. 1 and 2, there is a circular graphite seal 384 in the first cavity 380. This graphite seal 384 has an annular seat 386 which seats with the annular seat 354 of the rolling cutter 304. The rolling cutter 304 is of metal and therefore there is a graphite-to-metal seal between the seal 384 and the rolling cutter 304. The seal 384 slopes away at 388 from the annular seat 386. Also, the outer surface 390 of the seal slopes away from the annular seat 386. The seal 384 has an outer edge. There is a flexible, yieldable covering material 392 on the surface 390 and around the said outer edge. Further, a hard, protective covering material 394 covers the flexible, yieldable material 392. The material 392 is adhered to the graphite seal 384, and the hard, protective material 394 is bonded to the flexible, yieldable material 392. A flexible, yieldable O-ring 396 is positioned between the hard, protective material 394 and the circular flange 324. This yieldable, flexible O-ring 396 urges the seal 384 against the annular seat 354. Further, a spring 398 is positioned in the recess 322 and bears against the hard, protective material 394 so as to more definitely position the hard, protective material 394 and the seal 384.

In the second cavity 382 there is a circular seal 410 having an annular seat 412 for seating with the annular seat 336 of the journal 302. The seal 410 has a sloping surface 414.

- Further, the seal 410 has an edge 416. There is positioned on the sloping surface 414 and the edge 416 a soft, flexible, yieldable material 418. There is a hard protective material 420 for covering the flexible, yieldable material 418. The material 418 is bonded to the seal 410, and the material 420 is bonded to the material 418.

There is positioned between the hard, protective material 420 and the inner, circular flange 368 an O-ring 422. The O- ring 422 is a soft, flexible material. Further, there is positioned in the recess 366 a spring 424 which bears against the wall 364 and also against the protective layer 420. The O-ring 422 urges the seal 410 against the annular seat 336. Further, the spring 424 assists in positioning the hard, protective material 420 and also assists in urging the seal 410 against the annular seat 336. It is seen in H6. 2 that the inner portion of the seal 410 slopes inwardly and away from the annular seat 412 at 428. When the seal 410 wears, there is generated a large annular seat 412 for seating with the annular seat 336. it is to be recalled that the journal 302 is of metal, and the seal 410 is of However, the annular seat 336 of the journal 302 is stationary and the seal 410 is revolving or rotating with the rolling cutter 304.

The yieldable, flexible protective layer 392 and the O-ring 396 and the yieldable, flexible material 418 and the O-ring 422 may be of rubber or a suitable plastic such as polyu rethane. The protective shield 394 and 420 may be of metal or one of the modern plastics which can provide adequate protection for the yieldable, flexible material covering the seal.

In FIG. 5, there is illustrated another seal 450. The seal 450 has an annular seat 452 for seating with the annular seat 336 of the journal 302. The seal 450 has a sloping outer surface 454 and an annular edge surface 456. There is attached to the annular edge surface 456 a yieldable, flexible ring 458. There is attached to the yieldable, flexible ring 458 a hard, protective ring 460. In FIG. it is seen that the retainer rings 458 and 460 project outwardly from the edge 456.

There is positioned betweenthe sloping surface 454 and the inter circular flange 368 a yieldable, flexible O-ring 462. The retainer ring 458 and 460 retain the flexible O-ring 462 from working beyond the surface 454 and the edge 456. Also, the O-ring 462 urges the seat 452 of the graphite seal 450 against the annular seat 336 of the journal 302.

The retainer ring 458 and the O-ring 462 may be of rubber or a suitable plastic such as polyurethane. The retainer ring 460 may be of metal or a suitable plastic which can protect the retainer ring 458. In FIG. 5, the graphite seal 450 rotates with the rotation of the rolling cutter 304 while the annular seat 336 is stationary and does not rotate as the journal 302 does not rotate. As the seal 450 is of graphite and the journal 302 of metal, there is a graphite-to-metal seal between the annular surface 452 and the annular surface 336.

In FIG. 1 it is seen that on the outer surface of the rolling cutter 304 that there are a number of circular grooves 470 and in these circular grooves 470 there are inserted bits 472. The bits 472 have an encircling ring or an O-ring base 474. The bits 472 have a cutting edge 476 formed by two flat surfaces 478. The flat surfaces 478 may be considered to be planes which rise to an edge 476. The bits 472 can be pressed into the circular grooves 470 or the bits 742 can be cooled to a sufficiently low temperature that the ring 474 can be dropped into the circular groove 470 and allowed to reach room temperature and thereby expand to have a forced or pressed fit with respect to the circular groove 470.

In the radial passageway 310 there is positioned a plug 500 for entrance and egress of the ball bearings 351 in the groove 350. In the inner face of the plug 500 there is a groove 502. On the shaft 308 there is a circular groove 504. An O-ring 506 is in the grooves 502 and 504 so as to position the plug 500.

The graphite-to-metal seals, as presented in FIGS. 1, 2, and 5, are especially useful in a restricted space or volume application. Where the available space for using seals is limited, the use of a graphite seal with a metal surface, and which metal surface is part of the machinery, is especially valuable as the use of two graphite seals may not be permitted by the space requirements. In the cutters 60 and 300 the rolling cutter and the journal vibrate with respect to each other and this vibration places undue forces upon the seals. The rotating cutter is not resiliently mounted and with the use of graphite seals the vibration problem is reduced as compared with the use of metal seals. Also, graphite may be readily machined and thereby provides the designer and user of seals a much wider range of seals in small quantity production than with metal seals. Another great advantage of the use of the graphite seal is that when the graphite seal is seated against a metal surface, the metal surface does not require the quality of surface finish as when the seal is a metal-to-metal surface. In a metal-tometal surface it is necessary to have a higher quality of finish on both metal surfaces so that the two surfaces will seat properly and seal properly. With the graphite-to-metal seal, this metal is harder than the graphite and the graphite will more quickly wear to the configuration required for seating with the metal surface. Therefore, the finish on the metal surface, in a graphite-to-metal seal, is not as exact and therefore not as expensive as the surface on a metal seal in a metal-tometal seal.

By way of recapitulation, the O-rings 396, 422, 202, 462, in conjunction with the seals prevent grit from entering the bearing area. Further, these O-rings assist in locating the seal assembly of either graphite-to-graphite seals or graphite-tometal seals in a radial manner so as to provide a concentric mounted seal base. In addition, these O-rings provide a reaction means to the turning moment on the carbon-to-graphite seal resulting from a friction at seal face and rotation of the seal face. In additiomthese O-rings provide a resilient mounting for the graphite seal assembly thereby tending to permit the seal assembly to vibrate with the relative frequency of the mating seal face on the rotor. With the use of a heat transfer fluid or a cooling fluid in the bearings and seal chamber, it is possible to dissipate some of the heat generated by the gra phite-to-graphite seals rubbing together or by the graphite-tometal seals rubbing together. This heat is transferred to the liquid oil and from the liquid oil to the metal of the cutter. In FIGS. 1 and 2 there is illustrated a spring or yielding means 398 and 424 for bearing against the protective metal caps of the graphite seals and for urging the graphite seal toward the metal face or metal seal. If the temperature becomes too high, the O-ring 422 and the O-ring 396 may become deformed and permanently set so as to not adequately force the carbon seal against the metal seal. The O-ring may take a permanent set and thereby lose its ability to force the graphite seal against the metal seal. By the use of these metal springs it is possible to continue to force the graphite seal against the metal seal and thereby take up any slack due to the deformation of the O- ring.

In FIGS. 5 and 7, there is illustrated a retainer ring, 230 and 232 and 458 and 460 in another set. This retainer ring provides a vertical surface for a spring to bear against so as to urge the graphite seal toward another graphite seal or to urge a graphite seal toward a metal sealing surface. Further, the retainer ring provides an inexpensive means of retaining the seal assembly during the assembly of the cutter and also provides a simulated groove effect for retaining the O-ring during the assembly procedures.

In FIGS. 1, 2 and 8, there is illustrated a steel retainer shell or a hard, protective shell 252 or 420 or 394. Such a hard, protective shell or hard, protective ring makes it possible to make an inexpensive molded carbon graphite seal with a minimum of machining. The hard, protective shell provides a concentric, close dimension (approximate size) surface for the O-ring mounting on the outer surface. Further, there is a vertical surface for receiving the end of a spring so as to urge the graphite seal to seat. The flexible, yieldable ring between the hard, protective shell and the graphite seal, rubber or plastic or other suitable material, permits nominal carbon graphite seal irregularities as to size and finish and concentricity to be acceptable and thereby reduce the cost of the seal component. Further, the flexible, yieldable ring or liner provides some insulation from the heat generated at the seal face. In conjunction with the O-ring, the liner material also functions as a thermal expansion relief cushion to compensate for the differential and thermal expansion of the carbon graphite seal and the metal or plastic hard, protective retainer.

From the foregoing, it is seen that I have presented a number of illustrations of the use of graphite seals in a cutter having a fixed journal and a rolling cutter portion. The graphite seals may be in a graphite-to-metal sealing relationship or may be in a graphite-to-graphite seal relationship.

Iclaim:

1. A cutter, said cutter comprising:

a. a rolling cutter having a bearing opening extending longitudinally of the rolling cutter from one end to the other end;

b. a journal;

0. said journal being in said bearing opening and extending throughout the length of said opening and projecting from both ends thereof;

d. said cutter being secured on said journal be antifriction radial bearings and by antifriction thrust bearings;

e. said antifriction thrust bearings serve to lock together the rolling cutter and the journal against longitudinal movement;

f. said rolling cutter and said journal near one end defining a first cavity and near the other end defining a second caviy;

g. said rolling cutter and said journal being of metal;

h. said rolling cutter having a first annular seat in said first cavity;

i. said journal having a first annular ring in said first cavity and serving as a first annular seat;

j. a first graphite seal having an annular seat for seating with the first annular seat of the rolling cutter to form a gra-. phite-to-metal seal;

it. said first graphite seal being in the general configuration of a torus;

l. a first flexible yieldable ring between said first annular ring and said first graphite seal;

in. said journal having a second annular seat in said second cavity;

u. said rolling cutter having a second annular ring in said second cavity and serving as a second annular seat;

0. a second graphite seal having an annular seat for seating with the second annular seat of the journal to form a graphite-to-metal seal;

p. said second graphiteseal being in the general configura tion of a torus;

q. a second flexible yieldable ring between said second annular ring and said second graphite seal; and

r. said graphite seal, flexible yieldable ring and annular ring functioning as a seal to preclude'extraneous material entering into said cutter.

2. A cutter according to claim 1 and comprising:

a. each of said first and second graphite seals having an edge surface;

b. a retainer ring attached to each graphite seal at said edge surface; and

c. said retainer ring projecting above said edge surface and toward said adjacent annular ring.

3. A cutter according to claim 2 and comprising:

a. said retainer ring comprising a flexible yieldable material and a hard protective material; and,

b. said flexible yieldable material being between said graphite seal and said hard protective material.

4. A cutter according to claim 1 and comprising:

a. each of said first and second graphite seals having a sloping edge surface;

b. a protective covering material attached to said sloping edge surface; and

c. said flexible yieldable ring being between said protective covering material and an adjacent annular ring.

5. A cutter according to claim 4 and comprising:

a. said protective covering material comprising a flexible yieldable material and a hard protective material; and

b. said flexible yieldable material being between said graphite seal and said hard protective material.

6. A cutter, said cutter comprising:

a. a rolling cutter having a bearing opening extending longitudinally of the rolling cutter from one end to the other end;

b. a journal assembly;

c. said journal assembly being in said bearing opening and extending throughout the length of said opening and projecting from both ends thereof;

d. said cutter being secured on said journal assembly by antifriction radial bearings and by antifriction thrust bearings;

e. said antifriction thrust bearings serve to lock together the rolling cutter and the journal assembly against longitudinal movement;

f. said rolling cutter and said journal assembly near one end defining a first cavity and near the other end defining a second cavity;

g. said rolling cutter and said journal assembly being of metal; h. said rolling cutter having a rolling cutter first seat in said first cavity; i. said journal assembly having a journal assembly first seat in said first cavity; j. two first graphite ring seals in said first cavity; k. each of said first graphite ring seals having a first sealing surface; 1. said first graphite ring seals being so positioned that said first sealing surfaces are in a sealing relationship; m. a first flexible yieldable ring between one of said first graphite ring seals and said journal assembly first seat; n. a second flexible yieldable ring between the other one of said first graphite rings and said rolling cutter first seat; 0. said roller cutter having a rolling cutter second seat in said second cavity; p. said journal assembly having a journal assembly second seat in said second cavity; q. two second graphite ring seals in said second cavity; r. each of said second graphite ring seals having a second sealing surface; s. said second graphite ring seals being so positioned that said second sealing surfaces are in a sealing relationship; t. a third flexible yieldable ring between one of said second graphite ring seals and journal assembly second seat; and u. a fourth flexible yieldable ring between the other one of said second graphite rings and said rolling cutter second seat. A cutter according to claim 6and comprising: each of said two first graphite seals having an edge surface;

b. each of said two second graphite seals having an edge surface;

c. a retainer ring attached to each graphite seal at said edge surface; and

d. said retainer ring projecting above said edge surface and toward an appropriate seat.

8. A cutter according to claim 7 and comprising:

a. said retainer ring comprising a flexible yieldable material and a hard protective material; and

b. said flexible yieldable material being between said graphite seal and said hard protective material.

9. A cutter according to claim 6 and comprising:

a. each of said graphite seals having a sloping edge surface;

b. a protective covering material attached to said sloping edge surface; and,

c. said flexible yieldable-ring being between said protective covering material and an adjacent annular ring.

10. A cutter according to claim 9 and comprising:

a. said protective covering material comprising a flexible yieldable material and a hard protective material; and

b. said flexible yieldable material being between said graphite seal and said hard protective material.

11. A combination of a saddle and a cutter, said combination comprising:

a. said cutter comprising a rolling cutter having a bearing opening extending longitudinally of the rolling cutter from one end to the other end;

b. a journal;

c. said journal being in said bearing opening and extending throughout the length of said opening and projecting from both ends thereof;

d. said cutter being secured on said journal by antifriction radial bearings and by antifriction thrust bearings;

c. said antifriction thrust bearings serve to lock together the rolling cutter and the journal against longitudinal movement;

f. said rolling cutter and said journal near one end defining a first cavity and near the other end defining a second caviy;

g. said rolling cutter and said journal being of metal;

h. said rolling cutter having a first annular seat in said first cavity;

i. said journal having a first annular ring in said first cavity and sewing as a first annular seat;

j. a first graphite seal having an annular seat for seating with the first annular seat of the rolling cutter to form a graphite-to-metal seal;

It. said first graphite seal being in the general configuration of a torus;

l. a first flexible yieldable ring between said first annular ring and said first graphite seal;

in. said journal having a second annular seat in said second cavity;

n. said rolling cutter having a second annular ring in said second cavity and serving asa second annular seat;

0. a second graphite seal having an annular seat for seating with the second annular seat of the journal to form a graphite to-metal seal;

p. said second graphite seal being in the general configuration of a torus;

q. a second flexible yieldable ring between said second annular ring and said second graphite seal;

r. said graphite seal, flexible yieldable ring and annular ring functioning as a seal to preclude extraneous material entering into said cutter;

s. said saddle comprising a base, a first leg and a second leg in a generally U-configuration;

t. each leg on its surface having a slot for receiving an end of said journal; and

u. a means to retain said journal and cutter in said saddle.

12. A combination according to claim 11 and comprising:

a. said slot in each leg expanding inwardly so that said slot is wider at its base than at its throat;

b. said journal having a hub on each end and each hub becoming larger in size as it progresses away from said cutter so as to fit in a respective slot; and

c. said means being a keeper for positioning said journal in said slot.

13. A combination according to claim 12 and comprising:

a. each of said first and second graphite seals having an edge surface;

b. a retainer ring attached to each graphite seal at said edge surface; and

c. said retainer ring projecting above said edge surface and toward said adjacent annular ring.

14. A combination according to claim 13 and comprising:

a. said retainer ring comprising a flexible yieldable material and a hard protective material; and

b. said flexible yieldable material being between said graphite seal and said hard protective material.

15. A combination according to claim 12 and comprising:

a. each of said first and second graphite seals having a sloping edge surface;

b. a protective covering material attached to said sloping edge surface; and

c. said flexible yieldable ring being between said protective covering material and an adjacent annular ring.

16. A combination according to claim 15 and comprising:

a. said protective covering material comprising a flexible yieldable material and a hard protective material; and

b. said flexible yieldable material being between said graphite seal and said protective material.

17. A combination of a saddle and a cutter, said combination comprising:

a. said cutter comprising a rolling cutter having a bearing opening extending longitudinally of the rolling cutter from one end to the other end;

b. a journal assembly;

c. said journal assembly being in said bearing opening and extending throughout the length of said opening and projecting from both ends thereof;

d. said cutter being secured on said journal assembly by antifriction radial bearings and by antifriction thrust bearings;

e. said antifriction thrust bearings serve to lock together the rolling cutter and the journal assembly against longitudinal movement;

f. said rolling cutter and said journal assembly near one end defining a first cavity and near the other end defining a second cavity; Y

g. said rolling cutter and said journal assembly being of metal;

h. said rolling cutter having a rolling cutter first seat in said first cavity;

i. said journal assembly having a journal assembly first seat in said first cavity;

j. two first graphite ring seals in said first cavity;

k. each of said first graphite ring seals having a first sealing surface;

1. said first graphite ring seals being so positioned that said first sealing surfaces are in a sealing relationship;

in. a first flexible yieldabie ring between one of said first graphite ring seals and said journal assembly first seat;

n. a second flexible yieldable ring between the other one of said first graphite rings and said rolling cutter first seat;

0. said rolling cutter having a rolling cutter second seat in said second cavity;

p. said journal assembly having a journal assembly second seat in said second cavity;

q. two second graphite ring seals in said second cavity;

r. each of said second graphite ring seals having a second sealing surface;

s. said second graphite ring seals being so positioned that said second sealing surfaces are in a sealing relationship;

t. a third flexible yieldable ring between one of said second graphite ring seals and journal assembly second seat;

u. a fourth flexible yieldable ring between the other one of said second graphite rings and said rolling cutter second seat;

v. said saddle comprising a base, a first leg and a second leg in a generally U-configuration;

w. each leg on its surface having a slot for receiving an end of said journal; and

x. a means to retain said journal and cutter in said saddle.

18. A combination of a saddle and a cutter according to claim 17 and comprising:

a. said slot in each leg expanding inwardly so that said slot is wider at its base than at its throat;

b. said journal having a hub on each end and each hub becoming larger in size as it progresses away from said cutter so as to fit in a respective slot; and

c. said means being a keeper for positioning said journal in said slot.

19. A combination of a saddle and a cutter according to claim 18 and comprising:

claim 19 and comprising:

a. said retainer ring comprising a flexible yieldable material and a hard protective material; and

b. said flexible yieldable material being between said graphite seal and said hard protective material.

21. A combination of a saddle and a cutter according to claim 18 and comprising:

a. each of said graphite seals having a sloping edge surface;

b. a protective covering material attached to said sloping edge surface; and I c. said flexible yieldable ring being between said protective covering material and an adjacent annular ring.

22. A combination of a saddle and a cutter according to claim 21 and comprising:

a. said protective covering material comprising a flexible yieldable material and a hard protective material; and b. said flexible yieldable material being between said graphite seal and said hard protective material.

23. A saddle for receiving a rolling cutter, said saddle comprising:

a. a base, a first leg and a second leg in a generally U-configuration; 

1. A cutter, said cutter comprising: a. a rolling cutter having a bearing opening extending longitudinally of the rolling cutter from one end to the other end; b. a journal; c. said journal being in said bearing opening and extending throughout the length of said opening and projecting from both ends thereof; d. said cutter being secured on said journal be antifriction radial bearings and by antifriction thrust bearings; e. said antifriction thrust bearings serve to lock together the rolling cutter and the journal against longitudinal movement; f. said rolling cutter and said journal near one end defining a first cavity and near the other end defining a second cavity; g. said rolling cutter and said journal being of metal; h. said rolling cutter having a first annular seat in said first cavity; i. said journal having a first annular ring in said first cavity and serving as a first annular seat; j. a first graphite seal having an annular seat for seating with the first annular seat of the rolling cutter to form a graphite-to-metal seal; k. said first graphite seal being in the general configuration of a torus; l. a first flexible yieldable ring between said first annular ring and said first graphite seal; m. said journal having a second annular seat in said second cavity; n. said rolling cutter having a second annular ring in said second cavity and serving as a second annular seat; o. a second graphite seal having an annular seat for seating with the second annular seat of the journal to form a graphiteto-metal seal; p. said second graphite seal being in the general configuration of a torus; q. a second flexible yieldable ring between said second annular ring and said second graphite seal; and r. said graphite seal, flexible yieldable ring and annular ring functioning as a seal to preclude extraneous material entering into said cutter.
 2. A cutter according to claim 1 and comprising: a. each of said first and second graphite seals having an edge surface; b. a retainer ring attached to each graphite seal at said edge surface; and c. said retainer ring projecting above said edge surface and toward said adjacent annular ring.
 3. A cutter according to claim 2 and comprising: a. said retainer ring comprising a flexible yieldable material and a hard protective material; and, b. said flexible yieldable material being between said graphite seal and said hard protective material.
 4. A cutter according to claim 1 and comprising: a. each of said first and second graphite seals having a sloping edge surface; b. a protective covering material attached to said sloping edge surface; and c. said flexible yieldable ring being between said protective covering material and an adjacent annular ring.
 5. A cutter according to claim 4 and comprising: a. said protective covering material comprising a flexible yieldable material and a hard protective material; and b. said flexible yieldable material being between said graphite seal and said hard protective material.
 6. A cutter, said cutter comprising: a. a rolling cutter having a bearing opening extending longitudinally of the rolling cutter from one end to the other end; b. a journal assembly; c. said journal assembly being in said bearing opening and extending throughout the length of said opening and projecting from both ends thereof; d. said cutter being secured on said journal assembly by antifriction radial bearings and by antifriction thrust bearings; e. said antifriction thrust bearings serve to lock together the rolling cutter and the journal assembly against longitudinal movement; f. said rolling cutter and said journal assembly near one end defining a first cavity and near the other end defining a second cavity; g. said rolling cutter and said journal assembly being of metal; h. said rolling cutter having a rolling cutter first seat in said first cavity; i. said journal assembly having a journal assembly first seat in said first cavity; j. two first graphite ring seals in said first cavity; k. each of said first graphite ring seals having a first sealing surface; l. said first graphite ring seals being so positioned that said first sealing surfaces are in a sealing relationship; m. a first flexible yieldable ring between one of said first graphite ring seals and said journal assembly first seat; n. a second flexible yieldable ring between the other one of said first graphite rings and said rolling cutter first seat; o. said roller cutter having a rolling cutter second seat in said second cavity; p. said journal assembly having a journal assembly second seat in said second cavity; q. two second graphite ring seals in said second cavity; r. each of said second graphite ring seals having a second sealing surface; s. said second graphite ring seals being so positioned that said second sealing surfaces Are in a sealing relationship; t. a third flexible yieldable ring between one of said second graphite ring seals and journal assembly second seat; and u. a fourth flexible yieldable ring between the other one of said second graphite rings and said rolling cutter second seat.
 7. A cutter according to claim 6 and comprising: a. each of said two first graphite seals having an edge surface; b. each of said two second graphite seals having an edge surface; c. a retainer ring attached to each graphite seal at said edge surface; and d. said retainer ring projecting above said edge surface and toward an appropriate seat.
 8. A cutter according to claim 7 and comprising: a. said retainer ring comprising a flexible yieldable material and a hard protective material; and b. said flexible yieldable material being between said graphite seal and said hard protective material.
 9. A cutter according to claim 6 and comprising: a. each of said graphite seals having a sloping edge surface; b. a protective covering material attached to said sloping edge surface; and, c. said flexible yieldable ring being between said protective covering material and an adjacent annular ring.
 10. A cutter according to claim 9 and comprising: a. said protective covering material comprising a flexible yieldable material and a hard protective material; and b. said flexible yieldable material being between said graphite seal and said hard protective material.
 11. A combination of a saddle and a cutter, said combination comprising: a. said cutter comprising a rolling cutter having a bearing opening extending longitudinally of the rolling cutter from one end to the other end; b. a journal; c. said journal being in said bearing opening and extending throughout the length of said opening and projecting from both ends thereof; d. said cutter being secured on said journal by antifriction radial bearings and by antifriction thrust bearings; e. said antifriction thrust bearings serve to lock together the rolling cutter and the journal against longitudinal movement; f. said rolling cutter and said journal near one end defining a first cavity and near the other end defining a second cavity; g. said rolling cutter and said journal being of metal; h. said rolling cutter having a first annular seat in said first cavity; i. said journal having a first annular ring in said first cavity and serving as a first annular seat; j. a first graphite seal having an annular seat for seating with the first annular seat of the rolling cutter to form a graphite-to-metal seal; k. said first graphite seal being in the general configuration of a torus; l. a first flexible yieldable ring between said first annular ring and said first graphite seal; m. said journal having a second annular seat in said second cavity; n. said rolling cutter having a second annular ring in said second cavity and serving as a second annular seat; o. a second graphite seal having an annular seat for seating with the second annular seat of the journal to form a graphite-to-metal seal; p. said second graphite seal being in the general configuration of a torus; q. a second flexible yieldable ring between said second annular ring and said second graphite seal; r. said graphite seal, flexible yieldable ring and annular ring functioning as a seal to preclude extraneous material entering into said cutter; s. said saddle comprising a base, a first leg and a second leg in a generally U-configuration; t. each leg on its surface having a slot for receiving an end of said journal; and u. a means to retain said journal and cutter in said saddle.
 12. A combination according to claim 11 and comprising: a. said slot in each leg expanding inwardly so that said slot is wider at its base than at its throat; b. said journal having a hub on each end and each hub becoming larger in size as it progResses away from said cutter so as to fit in a respective slot; and c. said means being a keeper for positioning said journal in said slot.
 13. A combination according to claim 12 and comprising: a. each of said first and second graphite seals having an edge surface; b. a retainer ring attached to each graphite seal at said edge surface; and c. said retainer ring projecting above said edge surface and toward said adjacent annular ring.
 14. A combination according to claim 13 and comprising: a. said retainer ring comprising a flexible yieldable material and a hard protective material; and b. said flexible yieldable material being between said graphite seal and said hard protective material.
 15. A combination according to claim 12 and comprising: a. each of said first and second graphite seals having a sloping edge surface; b. a protective covering material attached to said sloping edge surface; and c. said flexible yieldable ring being between said protective covering material and an adjacent annular ring.
 16. A combination according to claim 15 and comprising: a. said protective covering material comprising a flexible yieldable material and a hard protective material; and b. said flexible yieldable material being between said graphite seal and said protective material.
 17. A combination of a saddle and a cutter, said combination comprising: a. said cutter comprising a rolling cutter having a bearing opening extending longitudinally of the rolling cutter from one end to the other end; b. a journal assembly; c. said journal assembly being in said bearing opening and extending throughout the length of said opening and projecting from both ends thereof; d. said cutter being secured on said journal assembly by antifriction radial bearings and by antifriction thrust bearings; e. said antifriction thrust bearings serve to lock together the rolling cutter and the journal assembly against longitudinal movement; f. said rolling cutter and said journal assembly near one end defining a first cavity and near the other end defining a second cavity; g. said rolling cutter and said journal assembly being of metal; h. said rolling cutter having a rolling cutter first seat in said first cavity; i. said journal assembly having a journal assembly first seat in said first cavity; j. two first graphite ring seals in said first cavity; k. each of said first graphite ring seals having a first sealing surface; l. said first graphite ring seals being so positioned that said first sealing surfaces are in a sealing relationship; m. a first flexible yieldable ring between one of said first graphite ring seals and said journal assembly first seat; n. a second flexible yieldable ring between the other one of said first graphite rings and said rolling cutter first seat; o. said rolling cutter having a rolling cutter second seat in said second cavity; p. said journal assembly having a journal assembly second seat in said second cavity; q. two second graphite ring seals in said second cavity; r. each of said second graphite ring seals having a second sealing surface; s. said second graphite ring seals being so positioned that said second sealing surfaces are in a sealing relationship; t. a third flexible yieldable ring between one of said second graphite ring seals and journal assembly second seat; u. a fourth flexible yieldable ring between the other one of said second graphite rings and said rolling cutter second seat; v. said saddle comprising a base, a first leg and a second leg in a generally U-configuration; w. each leg on its surface having a slot for receiving an end of said journal; and x. a means to retain said journal and cutter in said saddle.
 18. A combination of a saddle and a cutter according to claim 17 and comprising: a. said slot in each leg expanding inwardly so that said slot is wider At its base than at its throat; b. said journal having a hub on each end and each hub becoming larger in size as it progresses away from said cutter so as to fit in a respective slot; and c. said means being a keeper for positioning said journal in said slot.
 19. A combination of a saddle and a cutter according to claim 18 and comprising: a. each of said two first graphite seals having an edge surface; b. each of said two second graphite seals having an edge surface; c. a retainer ring attached to each graphite seal at said edge surface; and d. said retainer ring projecting above said edge surface and toward an appropriate seat.
 20. A combination of a saddle and a cutter according to claim 19 and comprising: a. said retainer ring comprising a flexible yieldable material and a hard protective material; and b. said flexible yieldable material being between said graphite seal and said hard protective material.
 21. A combination of a saddle and a cutter according to claim 18 and comprising: a. each of said graphite seals having a sloping edge surface; b. a protective covering material attached to said sloping edge surface; and c. said flexible yieldable ring being between said protective covering material and an adjacent annular ring.
 22. A combination of a saddle and a cutter according to claim 21 and comprising: a. said protective covering material comprising a flexible yieldable material and a hard protective material; and b. said flexible yieldable material being between said graphite seal and said hard protective material.
 23. A saddle for receiving a rolling cutter, said saddle comprising: a. a base, a first leg and a second leg in a generally U-configuration; b. each leg on its surface having a slot for receiving an end of said journal; and c. a keeper for positioning said rolling cutter in said slot.
 24. A saddle according to claim 23 and comprising said slot in each leg expanding inwardly so that said slot is wider at its base than at its throat. 